ABSTRACT

The enthalpies of solution DsolHm m were determined for 1,1,3,3-tetramethylurea in ethanol, 1-propanol, 2-propanol, 1-butanol, and t-butanol (2-methyl-2-propanol). Measurements were made at 298.15 K and molalities m @ (0.007 to 0.036) mol Ae kg 1 with a precise isoperibol ampoule-type calorimeter. Standard enthalpies of solution DsolH m and transfer DtrH m from one alkanol to the other (including methanol) were calculated. The obvious relationship between the enthalpic and volumetric effects of solution of tetramethylurea in the n-alkanols (C1 C4) was discovered. The enthalpic effects of transfer caused by branching of the alkanol molecules, 1-propanol! 2-propanol, and 1-butanol !t-butanol, are opposite in sign and dominated by the configurational changes in the solvation environment of tetramethylurea.

Compounds

#	Formula	Name
1	C5H12N2O	tetramethylurea
2	C2H6O	ethanol
3	C3H8O	propan-1-ol
4	C3H8O	propan-2-ol
5	C4H10O	butan-1-ol
6	C4H10O	2-methylpropan-2-ol

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	3 1	Molar enthalpy of solution, kJ/mol ; Liquid	Amount ratio of solute to solvent - 1; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	ISOPERIBOL	5
POMD	5 1	Molar enthalpy of solution, kJ/mol ; Liquid	Amount ratio of solute to solvent - 1; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	ISOPERIBOL	5
POMD	2 1	Molar enthalpy of solution, kJ/mol ; Liquid	Amount ratio of solute to solvent - 1; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	ISOPERIBOL	5
POMD	4 1	Molar enthalpy of solution, kJ/mol ; Liquid	Amount ratio of solute to solvent - 1; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	ISOPERIBOL	5
POMD	6 1	Molar enthalpy of solution, kJ/mol ; Liquid	Amount ratio of solute to solvent - 1; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid	Liquid	ISOPERIBOL	5

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Enthalpies of solution of 1,1,3,3-tetramethylurea in normal and branched alkanols (C2 C4) at 298.15 K

Ivanov, E. V.[Evgeniy V.], Abrosimov, V. K.[Vladimir K.], Smirnov, V. I.[Valeriy I.]

ABSTRACT